Flow: What is the equivalent of PropTypes.func in flow?

Question

I am trying to migrate from PropTypes to Flow type checking in my React components.

Please what is the equivalent of PropTypes.func in Flow, to specify that a prop is a Function ?

My code looks like this:

import * as React from 'react'

type Props = {
  doSomething: /* function */
}

class MyComponent extends React.Component<Props> {}

Answer 1

You can use:

type Props = {
  doSomething: () => void,
}

or specify arguments if needed.

Answer 2

There is a clearer way:

type Props = {
  doSomething: Function // with capital letter
}